A method of manufacturing an absorbent article, such as a sanitary napkin and a diaper, includes a process of folding a sheet continuum or a web along a machine direction which is in line with a flow direction of manufacturing processes of the absorbent article, while conveying the sheet continuum or the web in the machine direction. For example, there is disclosed an apparatus which forms a gather by disposing a string-like elastic member on a web (see Patent Document 1).
Patent Document 1 discloses the following folding apparatus. Specifically, in the folding apparatus, a conveying path which a web travels becomes narrower in width from its upstream side toward its downstream side in a machine direction. The folding apparatus folds the web so that a side region of the web overlaps a central region of the web, the side region and the central region extending in the machine direction of the web. The web is folded by being controlled by guides for forming folds while being conveyed in the machine direction.
The technique disclosed in Patent Document 1, however, has the following problem. Specifically, at points of the web from which the web is folded (hereinafter the points are collectively called a “fold origin”), the web becomes narrower in width. Moreover, at the fold origin, the side regions of the web having been conveyed in a flat manner are folded toward the central region. Here, the conveying path on the downstream side of the fold origin is bent relative to the conveying path on the upstream side of the fold origin. For this reason, a large stress is applied on the web at the fold origin of the web.
The web is conveyed while being rubbed by proximal ends of the guides. When the conveying speed is increased, this rubbing causes more damage particularly at the fold origin of the web, thereby causing manufacturing failures such as tearing.